<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>圆形与胶囊形</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            background-color: #833a3a;

            border-radius: 50%;
        }
        button {
            width: 200px;
            height: 80px;
            border: none;
            background-color: #00ff58;



            border-radius: 40px;
        }
    </style>
</head>
<body>
<div></div>
<button type="button"></button>

</body>
</html>